Chapter 10

Mars has an average atmospheric pressure of 0.007 atm. Would it be easier or harder to drink from a straw on Mars than on Earth? Explain. [Section 10.2]

Imagine that the reaction \(2 \mathrm{CO}(g)+\mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{CO}_{2}(g)\) occurs in a container that has a piston that moves to maintain a constant pressure when the reaction occurs at constant temperature. Which of the following statements describes how the volume of the container changes due to the reaction: (a) the volume increases by \(50 \%,(\mathbf{b})\) the volume increases by \(33 \%,\) (c) the volume remains constant, (d) the volume decreases by \(33 \%,(\) e) the volume decreases by 50\(\% .[\) Sections 10.3 and 10.4\(]\)

On a single plot, qualitatively sketch the distribution of molecular speeds for (a) \(\operatorname{Kr}(g)\) at \(-50^{\circ} \mathrm{C},(\mathbf{b}) \mathrm{Kr}(g)\) at \(0^{\circ} \mathrm{C},\) (c) \(\operatorname{Ar}(g)\) at \(0^{\circ} \mathrm{C} .[\) Section 10.7\(]\)

Which of the following statements is false? \begin{equation}\begin{array}{l}{\text { (a) Gases are far less dense than liquids. }} \\ {\text { (b) Gases are far more compressible than liquids. }} \\\ {\text { (c) Because liquid water and liquid carbon tetrachloride do }} \\\ {\text { not mix, neither do their vapors. }} \\ {\text { (d) The volume occupied by a gas is determined by the volume }} \\ {\text { of its container. }}\end{array}\end{equation}

(a) Are you more likely to see the density of a gas reported in \(\mathrm{g} / \mathrm{mL}, \mathrm{g} / \mathrm{L},\) or \(\mathrm{kg} / \mathrm{cm}^{3} ?(\mathbf{b})\) Which units are appropriate for expressing atmospheric pressures, \(\mathrm{N}, \mathrm{Pa},\) atm, kg/m \(^{2} ?\) (c) Which is most likely to be a gas at room temperature and ordinary atmospheric pressure, \(\mathrm{F}_{2}, \mathrm{Br}_{2}, \mathrm{K}_{2} \mathrm{O} .\)

Suppose that a woman weighing 130 \(\mathrm{lb}\) and wearing high- heeled shoes momentarily places all her weight on the heel of one foot. If the area of the heel is \(0.50 \mathrm{in.}^{2},\) calculate the pressure exerted on the underlying surface in (a) pounds per square inch, (b) kilopascals, and (c) atmospheres.

A set of bookshelves rests on a hard floor surface on four legs, each having a cross-sectional dimension of \(3.0 \times 4.1 \mathrm{cm}\) in contact with the floor. The total mass of the shelves plus the books stacked on them is 262 kg. Calculate the pressure in pascals exerted by the shelf footings on the surface.

(a) How high in meters must a column of glycerol be to exert a pressure equal to that of a \(760-\mathrm{mm}\) column of mercury? The density of glycerol is 1.26 \(\mathrm{g} / \mathrm{mL}\) , whereas that of mercury is 13.6 \(\mathrm{g} / \mathrm{mL}\) . (b) What pressure, in atmospheres, is exerted on the body of a diver if she is 15 ft below the surface of the water when the atmospheric pressure is 750 torr? Assume that the density of the water is \(1.00 \mathrm{g} / \mathrm{cm}^{3}=1.00 \times 10^{3} \mathrm{kg} / \mathrm{m}^{3} .\) The gravitational constant is \(9.81 \mathrm{m} / \mathrm{s}^{2},\) and \(1 \mathrm{Pa}=1 \mathrm{kg} / \mathrm{m}-\mathrm{s}^{2} .\)

(a) The compound 1-iodododecane is a nonvolatile liquid with a density of 1.20 \(\mathrm{g} / \mathrm{mL}\) . The density of mercury is 13.6 \(\mathrm{g} / \mathrm{mL} .\) What do you predict for the height of a barometer column based on 1 -iodododecane, when the atmospheric pressure is 749 torr? (b) What is the pressure, in atmospheres, on the body of a diver if he is 21 ft below the surface of the water when the atmospheric pressure is 742 torr?

The typical atmospheric pressure on top of Mount Everest \((29,028 \mathrm{ft})\) is about 265 torr. Convert this pressure to \((\mathbf{a})\) atm, \((\mathbf{b})\) \(\mathrm{mm} \mathrm{Hg}\),\((\mathbf{c})\) pascals,\((\mathbf{d})\) bars , \((\mathbf{e})\) psi.

Perform the following conversions: \((\mathbf{a})\) 0.912 atm to torr, \((\mathbf{b})\) 0.685 bar to kilopascals, \((\mathbf{c})\) 655 \(\mathrm{mm}\) Hg to atmospheres, \((\mathbf{d})\) \(1.323 \times 10^{5}\) Pa to atmospheres, \((\mathbf{e})\) 2.50 atm to psi.

In the United States, barometric pressures are generally reported in inches of mercury (in. Hg). On a beautiful summer day in Chicago, the barometric pressure is 30.45 in. Hg. \((\mathbf{a})\) Convert this pressure to torr. \((\mathbf{b})\) Convert this pressure to atm.

Hurricane Wilma of 2005 is the most intense hurricane on record in the Atlantic basin, with a low-pressure reading of 882 mbar (millibars). Convert this reading into \((\mathbf{a})\) atmospheres, \((\mathbf{b})\) torr, and \((\mathbf{c})\) inches of Hg.

You have a gas at \(25^{\circ} \mathrm{C}\) confined to a cylinder with a movable piston. Which of the following actions would double the gas pressure? \((\mathbf{a})\) Lifting up on the piston to double the volume while keeping the temperature constant; \((\mathbf{b})\) Heating the gas so that its temperature rises from \(25^{\circ} \mathrm{C}\) to \(50^{\circ} \mathrm{C}\) , while keeping the volume constant; \((\mathbf{c})\) Pushing down on the piston to halve the volume while keeping the temperature constant.

A fixed quantity of gas at \(21^{\circ} \mathrm{C}\) exhibits a pressure of 752 torr and occupies a volume of 5.12 L. \((\mathbf{a})\) Calculate the volume the gas will occupy if the pressure is increased to 1.88 atm while the temperature is held constant. \((\mathbf{b})\) Calculate the volume the gas will occupy if the temperature is increased to\(175^{\circ} \mathrm{C}\) while the pressure is held constant.

\((\mathbf{a})\) Amonton's law expresses the relationship between pressure and temperature. Use Charles's law and Boyle's law to derive the proportionality relationship between \(P\) and \(T\) . \((\mathbf{b})\) If a car tire is filled to a pressure of 32.0 \(\mathrm{lb} / \mathrm{in.}^{2}\) (psi) measured at \(75^{\circ} \mathrm{F},\) what will be the tire pressure if the tires heat up to \(120^{\circ} \mathrm{F}\) during driving?

Nitrogen and hydrogen gases react to form ammonia gas as follows: $$\mathrm{N}_{2}(g)+3 \mathrm{H}_{2}(g) \longrightarrow 2 \mathrm{NH}_{3}(g)$$ At a certain temperature and pressure, 1.2 \(\mathrm{L}\) of \(\mathrm{N}_{2}\) reacts with 3.6 \(\mathrm{Lof} \mathrm{H}_{2} .\) If all the \(\mathrm{N}_{2}\) and \(\mathrm{H}_{2}\) are consumed, what volume of \(\mathrm{NH}_{3},\) at the same temperature and pressure, will be produced?

(a) What conditions are represented by the abbreviation STP? (b) What is the molar volume of an ideal gas at STP? (c) Room temperature is often assumed to be \(25^{\circ} \mathrm{C}\) . Calculate the molar volume of an ideal gas at \(25^{\circ} \mathrm{C}\) and 1 atm pressure. (d) If you measure pressure in bars instead of atmospheres, calculate the corresponding value of \(R\) in L-bar/mol-K.

Suppose you are given two \(1-\) flasks and told that one contains a gas of molar mass 30 , the other a gas of molar mass 60 , both at the same temperature. The pressure in flask \(A\) is \(x\) atm, and the mass of gas in the flask is 1.2 \(\mathrm{g}\) . The pressure in flask \(\mathrm{B}\) is 0.5\(x\) atm, and the mass of gas in that flask is 1.2 \(\mathrm{g}\) . Which flask contains the gas of molar mass \(30,\) and which contains the gas of molar mass 60\(?\)

Complete the following table for an ideal gas: $$\begin{array}{cccc}{P} & {v} & {n} & {T} \\ {2.00 \text { atm }} & {1.00 \mathrm{L}} & {0.500 \mathrm{mol}} & {\text { ?K }} \\ {0.300 \mathrm{atm}} & {0.250 \mathrm{L}} & {? \mathrm{mol}}\\\\{650 \text { torr }} & {\text { ?L }} & {0.333 \mathrm{mol}} & {350 \mathrm{K}} \\ {\text { ? atm }} & {585 \mathrm{mL}} & {0.250 \mathrm{mol}} & {295 \mathrm{K}}\end{array}$$

Calculate each of the following quantities for an ideal gas: (a) the volume of the gas, in liters, if 1.50 mol has a pressure of 1.25 atm at a temperature of \(-6^{\circ} \mathrm{C} ; \mathbf{b}\) ) the absolute temperature of the gas at which \(3.33 \times 10^{-3}\) mol occupies 478 \(\mathrm{mL}\) at 750 torr; (c) the pressure, in atmospheres, if 0.00245 \(\mathrm{mol}\) occupies 413 \(\mathrm{mL}\) at \(138^{\circ} \mathrm{C} ;(\mathbf{d})\) the quantity of gas, in moles, if 126.5 \(\mathrm{L}\) at \(54^{\circ} \mathrm{C}\) has a pressure of 11.25 \(\mathrm{kPa}\) .

A neon sign is made of glass tubing whose inside diameter is 2.5 \(\mathrm{cm}\) and whose length is 5.5 \(\mathrm{m}\) . If the sign contains neon at a pressure of 1.78 torr at \(35^{\circ} \mathrm{C}\) , how many grams of neon are in the sign? (The volume of a cylinder is \(\pi r^{2} h . )\)

(a) Calculate the number of molecules in a deep breath of air whose volume is 2.25 L at body temperature, \(37^{\circ} \mathrm{C},\) and a pressure of 735 torr. (b) The adult blue whale has a lung capacity of \(5.0 \times 10^{3} \mathrm{L}\) . Calculate the mass of air (assume an average molar mass of 28.98 \(\mathrm{g} / \mathrm{mol}\) ) contained in an adult blue whale's lungs at \(0.0^{\circ} \mathrm{C}\) and \(1.00 \mathrm{atm},\) assuming the air behaves ideally.

(a) If the pressure exerted by ozone, \(\mathrm{O}_{3},\) in the stratosphere is \(3.0 \times 10^{-3}\) atm and the temperature is 250 \(\mathrm{K}\) , how many ozone molecules are in a liter? (b) Carbon dioxide makes up approximately 0.04\(\%\) of Earth's atmosphere. If you collect a \(2.0-\mathrm{L}\) sample from the atmosphere at sea level \((1.00 \mathrm{atm})\) on a warm day \(\left(27^{\circ} \mathrm{C}\right),\) how many \(\mathrm{CO}_{2}\) molecules are in your sample?

A scuba diver's tank contains 0.29 \(\mathrm{kg}\) of \(\mathrm{O}_{2}\) compressed into a volume of 2.3 \(\mathrm{L}\) . (a) Calculate the gas pressure inside the tank at \(9^{\circ} \mathrm{C} (\mathbf{b})\) What volume would this oxygen occupy at \(26^{\circ} \mathrm{C}\) and 0.95 atm?

An aerosol spray can with a volume of 250 \(\mathrm{mL}\) contains 2.30 \(\mathrm{g}\) of propane gas \(\left(\mathrm{C}_{3} \mathrm{H}_{8}\right)\) as a propellant. (a) If the can is at \(23^{\circ} \mathrm{C}\) , what is the pressure in the can? (b) What volume would the propane occupy at STP? (c) The can's label says that exposure to temperatures above \(130^{\circ}\) F may cause the can to burst. What is the pressure in the can at this temperature?

A 35.1 g sample of solid \(\mathrm{CO}_{2}(\) dry ice \()\) is added to a container at a temperature of 100 \(\mathrm{K}\) with a volume of 4.0 \(\mathrm{L} .\) If the container is evacuated (all of the gas removed), sealed and then allowed to warm to room temperature \((T=298 \mathrm{K})\) so that all of the solid \(\mathrm{CO}_{2}\) is converted to a gas, what is the pressure inside the container?

Chlorine is widely used to purify municipal water supplies and to treat swimming pool waters. Suppose that the volume of a particular sample of \(\mathrm{Cl}_{2}\) gas is 8.70 \(\mathrm{L}\) at 895 torr and \(24^{\circ} \mathrm{C}\) .(a) How many grams of \(\mathrm{Cl}_{2}\) are in the sample? (b) What volume will the \(\mathrm{Cl}_{2}\) occupy at \(\mathrm{STP}\) ? (c) At what temperature will the volume be 15.00 \(\mathrm{L}\) if the pressure is \(8.76 \times 10^{2}\) torr? (d) At what pressure will the volume equal 5.00 L if the temperature is \(58^{\circ} \mathrm{C}\) ?

Many gases are shipped in high-pressure containers. Consider a steel tank whose volume is 55.0 gallons that contains \(\mathrm{O}_{2}\) gas at a pressure of \(16,500 \mathrm{kPa}\) at \(23^{\circ} \mathrm{C}\) . (a) What mass of \(\mathrm{O}_{2}\) does the tank contain? (b) What volume would the gas occupy at STP? (c) At what temperature would the pressure in the tank equal 150.0 atm? (d) What would be the pressure of the gas, in kPa, if it were transferred to a container at \(24^{\circ} \mathrm{C}\) whose volume is 55.0 \(\mathrm{L}\) ?

In an experiment reported in the scientific literature, male cockroaches were made to run at different speeds on a miniature treadmill while their oxygen consumption was measured. In 1 hr the average cockroach running at 0.08 \(\mathrm{km} / \mathrm{hr}\) consumed 0.8 \(\mathrm{mL}\) of \(\mathrm{O}_{2}\) at 1 atm pressure and \(24^{\circ} \mathrm{C}\) per gram of insect mass. (a) How many moles of \(\mathrm{O}_{2}\) would be consumed in 1 hr by a 5.2 -g cockroach moving at this speed? (b) This same cockroach is caught by a child and placed in a 1 -qt fruit jar with a tight lid. Assuming the same level of continuous activity as in the research, will the cockroach consume more than 20\(\%\) of the available \(\mathrm{O}_{2}\) in a 48 -hr period? (Air is 21 \(\mathrm{mol} \% \mathrm{O}_{2}\) . \()\)

The physical fitness of athletes is measured by \(^{u} V_{\mathrm{O}_{2}} \max _{2}^{\prime \prime}\) which is the maximum volume of oxygen consumed by an individual during incremental exercise (for example, on a treadmill). An average male has a \(V_{\mathrm{O}_{2}}\) max of 45 \(\mathrm{mL} \mathrm{O}_{2 / \mathrm{kg}}\) body mass/min, but a world-class male athlete can have a \(V_{\mathrm{O}_{2}}\) max reading of 88.0 \(\mathrm{mL} \mathrm{O}_{2} / \mathrm{kg}\) body mass/min. (a) Calculate the volume of oxygen, in mL, consumed in 1 by an average man who weighs 185 lbs and has a \(V_{\mathrm{O}_{2}}\) max reading of 47.5 \(\mathrm{mLO}_{2} / \mathrm{kg}\) body mass/min. (b) If this man lost \(20 \mathrm{lb},\) exercised, and increased his \(V_{\mathrm{O}_{2}}\) max to 65.0 \(\mathrm{mL}\) O \(_{2} / \mathrm{kg}\) body mass/min, how many mL of oxygen would he consume in 1 \(\mathrm{hr}\) ?

Rank the following gases from least dense to most dense at 1.00 atm and \(298 \mathrm{K} : \mathrm{SO}_{2}, \mathrm{HBr}, \mathrm{CO}_{2} .\)

Which of the following statements best explains why a closed balloon filled with helium gas rises in air? \begin{equation}\begin{array}{l}{\text { (a) Helium is a monatomic gas, whereas nearly all the molecules }} \\ {\text { that make up air, such as nitrogen and oxygen, are }} \\ {\text { diatomic. }} \\ {\text { (b) The average speed of helium atoms is greater than the }} \\ {\text { average speed of air molecules, and the greater speed }} \\ {\text { of collisions with the balloon walls propels the balloon }} \\ {\text { upward. }}\\\\{\text { (c) Because the helium atoms are of lower mass than the average }} \\ {\text { air molecule, the helium gas is less dense than air. }} \\\ {\text { The mass of the balloon is thus less than the mass of the }} \\\ {\text { air displaced by its volume. }}\\\\{\text { (d) Because helium has a lower molar mass the average }} \\ {\text { air molecule, the helium atoms are in faster motion. This }} \\ {\text { means that the temperature of the helium is greater than }} \\ {\text { the air temperature. Hot gases tend to rise. }}\end{array} \end{equation}

Which of the following statements best explains why nitrogen gas at STP is less dense than Xe gas at STP? \begin{equation}\begin{array}{l}{\text { (a) Because Xe is a noble gas, there is less tendency for the Xe }} \\ {\text { atoms to repel one another, so they pack more densely in }} \\ {\text { the gaseous state. }} \\ {\text { (b) Xe atoms have a higher mass than } \mathrm{N}_{2} \text { molecules. Because }} \\ {\text { both gases at STP have the same number of molecules per }} \\ {\text { unit volume, the Xe gas must be denser. }}\\\\{\text { (c) The Xe atoms are larger than } \mathrm{N}_{2} \text { molecules and thus take }} \\ {\text { up a larger fraction of the space occupied by the gas. }} \\\ {\text { (d) Because the Xe atoms are much more massive than the }} \\\ {\mathrm{N}_{2} \text { molecules, they move more slowly and thus exert }} \\\ {\text { less upward force on the gas container and make the gas }} \\ {\text { appear denser. }}\end{array}\end{equation}

\begin{equation}\begin{array}{l}{\text { (a) Calculate the density of } \mathrm{NO}_{2} \text { gas at } 0.970 \text { atm and } 35^{\circ} \mathrm{C} \text { . }} \\ {\text { (b) Calculate the molar mass of a gas if } 2.50 \mathrm{g} \text { occupies } 0.875} \\ {\text { L at } 685 \text { torr and } 35^{\circ} \mathrm{C} \text { . }}\end{array}\end{equation}

(a) Calculate the density of sulfur hexafluoride gas at 707 torr and \(21^{\circ} \mathrm{C}\) . (b) Calculate the molar mass of a vapor that has a density of 7.135 \(\mathrm{g} / \mathrm{L}\) at \(12^{\circ} \mathrm{C}\) and 743 torr.

In the Dumas-bulb technique for determining the molar mass of an unknown liquid, you vaporize the sample of a liquid that boils below \(100^{\circ} \mathrm{C}\) in a boiling-water bath and determine the mass of vapor required to fill the bulb. From the following data, calculate the molar mass of the unknown liquid: mass of unknown vapor, 1.012 g; volume of bulb, \(354 \mathrm{cm}^{3} ;\) pressure, 742 torr; temperature, \(99^{\circ} \mathrm{C}\) .

The molar mass of a volatile substance was determined by the Dumas-bulb method described in Exercise \(10.53 .\) The unknown vapor had a mass of 0.846 g; the volume of the bulb was \(354 \mathrm{cm}^{3},\) pressure 752 torr, and temperature \(100^{\circ} \mathrm{C}\) . Calculate the molar mass of the unknown vapor.

Magnesium can be used as a "getter" in evacuated enclosures to react with the last traces of oxygen. (The magnesium is usually heated by passing an electric current through a wire or ribbon of the metal.) If an enclosure of 0.452 L. has a partial pressure of \(\mathrm{O}_{2}\) of \(3.5 \times 10^{-6}\) torr at \(27^{\circ} \mathrm{C},\) what mass of magnesium will react according to the following equation? $$2 \mathrm{Mg}(s)+\mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{MgO}(s)$$

Calcium hydride, CaH \(_{2},\) reacts with water to form hydrogen gas: $$\mathrm{CaH}_{2}(s)+2 \mathrm{H}_{2} \mathrm{O}(l) \longrightarrow \mathrm{Ca}(\mathrm{OH})_{2}(a q)+2 \mathrm{H}_{2}(g)$$ This reaction is sometimes used to inflate life rafts, weather balloons, and the like, when a simple, compact means of generating \(\mathrm{H}_{2}\) is desired. How many grams of \(\mathrm{CaH}_{2}\) are needed to generate 145 \(\mathrm{L}\) of \(\mathrm{H}_{2}\) gas if the pressure of \(\mathrm{H}_{2}\) is 825 torr at \(21^{\circ} \mathrm{C} ?\)

The metabolic oxidation of glucose, \(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6},\) in our bodies produces \(\mathrm{CO}_{2},\) which is expelled from our lungs as a gas: $$\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}(a q)+6 \mathrm{O}_{2}(g) \longrightarrow 6 \mathrm{CO}_{2}(g)+6 \mathrm{H}_{2} \mathrm{O}(l)$$ (a) Calculate the volume of dry \(\mathrm{CO}_{2}\) produced at body temperature \(\left(37^{\circ} \mathrm{C}\right)\) and 0.970 atm when 24.5 \(\mathrm{g}\) of glucose is consumed in this reaction. (b) Calculate the volume of oxygen you would need, at 1.00 \(\mathrm{atm}\) and \(298 \mathrm{K},\) to completely oxidize 50.0 \(\mathrm{g}\) of glucose.

Both Jacques Charles and Joseph Louis Guy-Lussac were avid balloonists. In his original flight in \(1783,\) Jacques Charles used a balloon that contained approximately \(31,150\) L of \(\mathrm{H}_{2}\) . He generated the \(\mathrm{H}_{2}\) using the reaction between iron and hy- drochloric acid: $$\mathrm{Fe}(s)+2 \mathrm{HCl}(a q) \longrightarrow \mathrm{FeCl}_{2}(a q)+\mathrm{H}_{2}(g)$$ How many kilograms of iron were needed to produce this volume of \(\mathrm{H}_{2}\) if the temperature was \(22^{\circ} \mathrm{C}\) ?

Hydrogen gas is produced when zinc reacts with sulfuric acid: $$\mathrm{Zn}(s)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \longrightarrow \mathrm{ZnSO}_{4}(a q)+\mathrm{H}_{2}(g)$$ If 159 \(\mathrm{mL}\) of wet \(\mathrm{H}_{2}\) is collected over water at \(24^{\circ} \mathrm{C}\) and a barometric pressure of 738 torr, how many grams of Zn have been consumed? (The vapor pressure of water is tabulated in Appendix B.)

Consider a mixture of two gases, \(A\) and \(B,\) confined in a closed vessel. A quantity of a third gas, \(C,\) is added to the same vessel at the same temperature. How does the addition of gas C affect the following: (a) the partial pressure of gas A, (b) the total pressure in the vessel, (c) the mole fraction of gas B?

A mixture containing 0.765 mol \(\mathrm{He}(g), 0.330 \mathrm{mol} \mathrm{Ne}(g),\) and 0.110 \(\mathrm{mol} \mathrm{Ar}(g)\) is confined in a \(10.00-\mathrm{L}\) vessel at \(25^{\circ} \mathrm{C}\) . (a) Calculate the partial pressure of each of the gases in the mixture. (b) Calculate the total pressure of the mixture.

A deep-sea diver uses a gas cylinder with a volume of 10.0 \(\mathrm{L}\) and a content of 51.2 \(\mathrm{g}\) of \(\mathrm{O}_{2}\) and 32.6 \(\mathrm{g}\) of He. Calculate the partial pressure of each gas and the total pressure if the temperature of the gas is \(19^{\circ} \mathrm{C}\) .

The atmospheric concentration of \(\mathrm{CO}_{2}\) gas is presently 407 \(\mathrm{ppm}(\) parts per million, by volume; that is, 407 \(\mathrm{L}\) of every \(10^{6} \mathrm{L}\) of the atmosphere are \(\mathrm{CO}_{2}\) . What is the mole fraction of \(\mathrm{CO}_{2}\) in the atmosphere?

A plasma-screen TV contains thousands of tiny cells filled with a mixture of \(\mathrm{Xe}, \mathrm{Ne}\) , and He gases that emits light of specific wavelengths when a voltage is applied. A particular plasma cell, \(0.900 \mathrm{mm} \times 0.300 \mathrm{mm} \times 10.0 \mathrm{mm},\) contains 4\(\%\) Xe in a 1: Ne: He mixture at a total pressure of 500 torr. Calculate the number of Xe, Ne, and He atoms in the cell and state the assumptions you need to make in your calculation.

A piece of dry ice (solid carbon dioxide) with a mass of 5.50 \(\mathrm{g}\) is placed in a 10.0 -L vessel that already contains air at 705 torr and \(24^{\circ} \mathrm{C}\) . After the carbon dioxide has totally sublimed, what is the partial pressure of the resultant CO\(_{2}\) gas, and the total pressure in the container at \(24^{\circ} \mathrm{C} ?\)

A sample of 5.00 \(\mathrm{mL}\) of diethylether \(\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OC}_{2} \mathrm{H}_{5},\right.\) density \(=0.7134 \mathrm{g} / \mathrm{mL}\) ) is introduced into a 6.00 -L vessel that already contains a mixture of \(\mathrm{N}_{2}\) and \(\mathrm{O}_{2},\) whose partial pressures are \(P_{\mathrm{N}_{2}}=0.751 \mathrm{atm}\) and \(P_{\mathrm{O}_{2}}=0.208\) atm. The temperature is held at \(35.0^{\circ} \mathrm{C},\) and the diethylether totally evaporates. (a) Calculate the partial pressure of the diethylether. (b) Calculate the total pressure in the container.